"You're totally on your own, Whole neighborhoods are going to go away."

Nine weeks after Hurricane Katrina flooded most of New Orleans, about half of the city's 110,000 homes have been inspected. Greg Meffert, assistant to Mayor Ray Nagin, says city officials estimate that 30,000 to 50,000 will have to be demolished.

There are no color-coded labels yet on the homes in the Adamses' Lakeview neighborhood, a middle-class enclave near Lake Pontchartrain and the breached 17th Street Canal.

"We don't know," says Danny Adams, 59, a longtime employee of the Internal Revenue Service who is waiting not just for city inspectors but for an insurance adjuster to assess the damage to his home.

Water had filled Adamses' first floor nearly to the ceiling. "We don't know what the procedure's going to be. We've heard all kinds of things," he said.

The uncertainty of not knowing is gnawing at people in neighborhoods like Lakeview as residents return to salvage what they can and haul out ruined furniture and belongings to the curbs of streets littered with debris.

"It's a very emotional topic," Meffert says. But, he says, "people are being very realistic."

Nagin met with city residents last week at a downtown hotel. It was his first town hall meeting since the storm.

He laid out the harsh math.

The deciding factors in whether homeowners should rebuild, Nagin said, are whether a home's elevation is above the level of the 100-year flood plain -- meaning a 1-in-100 chance of flooding in a given year -- and whether the homeowner had flood insurance.

Those with flood insurance whose homes are at or above the flood plain can get a quick OK to rebuild, Nagin said.

Those below the flood plain with no flood insurance -- a circumstance common in poor areas such as the 9th Ward -- will have to raise the level of their home foundations, at an average cost of about $40,000, before rebuilding.

"If you're below the flood plain with no insurance, I'm afraid I don't have a lot of options for you," Nagin told several hundred residents.

"You're totally on your own," says Meffert, the mayor's aide. "Whole neighborhoods are going to go away."